From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 5C87BC38145 for ; Wed, 7 Sep 2022 12:42:58 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender: Content-Transfer-Encoding:Content-Type:Cc:List-Subscribe:List-Help:List-Post: List-Archive:List-Unsubscribe:List-Id:In-Reply-To:MIME-Version:References: Message-ID:Subject:To:From:Date:Reply-To:Content-ID:Content-Description: Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID: List-Owner; bh=6kisQ0eV6TG716saJdeL6WxsGOKQ+cRnt+sgkFdRR6M=; b=oLb3m4Aqc6x+WF /vBFy6AE6vRbFxIxO081jVROVHUQ9K57hVOpibMV/l1qFZhH4UaTc1uEDD1o4G1x1Ug+RpVc2+//t HTpaQ9S7Pnpk5VIJSvPeUfsYU4WJMEQmRvNjIEPwIqkqG2ITaB86XnTrVWuNPk4qH2KYmxxca6er3 NRNA/bnmZBUUy7GkdhxzlcF3y+b9hwCDLgKg08JeJAWW4q25EMEpOCATWN0nMOVNFM+VNOQT5jcnt /kDD8nQ4wMpmGkZPOvZ3Y4uDaFBbqJlOR6LWF8SDVO25go07CLVXllZ8jcOLETPjXqNbQS4nckRsO wJwbhUPdSFyDS5CBIGRw==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.94.2 #2 (Red Hat Linux)) id 1oVuNU-006CMK-Tf; Wed, 07 Sep 2022 12:42:01 +0000 Received: from mail.8bytes.org ([2a01:238:42d9:3f00:e505:6202:4f0c:f051]) by bombadil.infradead.org with esmtp (Exim 4.94.2 #2 (Red Hat Linux)) id 1oVuNR-006CKe-6c for linux-arm-kernel@lists.infradead.org; Wed, 07 Sep 2022 12:41:58 +0000 Received: from 8bytes.org (p4ff2bb62.dip0.t-ipconnect.de [79.242.187.98]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange ECDHE (P-256) server-signature RSA-PSS (2048 bits) server-digest SHA256) (No client certificate requested) by mail.8bytes.org (Postfix) with ESMTPSA id 6FAA4240857; Wed, 7 Sep 2022 14:41:55 +0200 (CEST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=8bytes.org; s=default; t=1662554516; bh=JzhvE6AKnt05k9hUcUfcBmLyd7x5XDIZ52BK23fxpSg=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=60gm7iJb3a9EHDRBPPmkRhjnPxPdo8Gl8tCIOOIov74tc9nJYqxwRN3f9BaD/uBTh ZoV5WBylA/H+HpQRYy6dC/0WalBc7Xg2gQ/EGr7HOKkp3DB6I7K2VtL5rWe+yHaFHo 3GC6YDahBrvwp1lTMhPP0vwiUslxcaImFmKevknjuQ++PrHb+32Kb+SwW1OGoiSniC j5WIwf2zsHXP7Dwv+Ps3tJybqv0ASdmzh/SRgK2OM7/c76yEAtXi01DBWO3CrfKkfR V7IV9Z/HY1tQSVYITH64oKsBfN+UYoyf/xQA2uGwpPthodTETsq7ja03Rs0zm47WBI eNx1oHFYz53Og== Date: Wed, 7 Sep 2022 14:41:54 +0200 From: Joerg Roedel To: Nicolin Chen Subject: Re: [PATCH v6 1/5] iommu: Return -EMEDIUMTYPE for incompatible domain and device/group Message-ID: References: <20220815181437.28127-1-nicolinc@nvidia.com> <20220815181437.28127-2-nicolinc@nvidia.com> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: <20220815181437.28127-2-nicolinc@nvidia.com> X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20220907_054157_498241_C90414A0 X-CRM114-Status: GOOD ( 10.80 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: linux-s390@vger.kernel.org, marcan@marcan.st, mjrosato@linux.ibm.com, linux-kernel@vger.kernel.org, thierry.reding@gmail.com, will@kernel.org, alyssa@rosenzweig.io, jean-philippe@linaro.org, kvm@vger.kernel.org, zhang.lyra@gmail.com, jon@solid-run.com, jonathanh@nvidia.com, iommu@lists.linux.dev, jgg@nvidia.com, yangyingliang@huawei.com, orsonzhai@gmail.com, gerald.schaefer@linux.ibm.com, kevin.tian@intel.com, sven@svenpeter.dev, linux-arm-msm@vger.kernel.org, alex.williamson@redhat.com, christophe.jaillet@wanadoo.fr, baolin.wang@linux.alibaba.com, thunder.leizhen@huawei.com, linux-tegra@vger.kernel.org, tglx@linutronix.de, virtualization@lists.linux-foundation.org, linux-arm-kernel@lists.infradead.org, dwmw2@infradead.org, cohuck@redhat.com, shameerali.kolothum.thodi@huawei.com, robdclark@gmail.com, asahi@lists.linux.dev, suravee.suthikulpanit@amd.com, robin.murphy@arm.com, baolu.lu@linux.intel.com Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org On Mon, Aug 15, 2022 at 11:14:33AM -0700, Nicolin Chen wrote: > Provide a dedicated errno from the IOMMU driver during attach that the > reason attached failed is because of domain incompatability. EMEDIUMTYPE > is chosen because it is never used within the iommu subsystem today and > evokes a sense that the 'medium' aka the domain is incompatible. I am not a fan of re-using EMEDIUMTYPE or any other special value. What is needed here in EINVAL, but with a way to tell the caller which of the function parameters is actually invalid. For that I prefer adding an additional pointer parameter to the attach functions in which the reason for the failure can be communicated up the chain. For the top-level iommu_attach_device() function I am okay with having a special version which has this additional paremter. Regards, Joerg _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel